Gas burning space heater



sept. 20;?14949.

2 Shee'ts-Sheet l Filed Nov'. 5,- 1945 Wann Iii

.sg/pal/z/ 44' mez Sept. 20, 1949. T. Yl KovRsGREN GAS BURNING SPACE HEATER 2 SheebS-Sheeil 2 Filed NOV. 5, 1945 Patented Sept. 20, 1.949

,I v aisfa'ssa I GASBURNING SPACE nEvA'rEn" Theodore Y. ,Korsgrem Winnetka,v Ill., assignor tov y Stewart-Warner .Cor-poration, Chicago, lll., a

.corporation of yVirginia Y AApplication November 5,19,45,serialNat'zeziz` f j n temine.. (cifras-11e) j J "IheV present invention relates to gas. heaters and more particularly tov gas heaters of the space:`

heater or iioor furnace type.v

. It is the principal object of the presentinven-v` tion to provide a novel heater. of the above. type in which the Ventilating air is completely separated from the combustionair throughout the heater system.

Another object .of the present inventionis .to

provide lan improved gas =heaterfwell adapted to to the'control system for such azfurnaceLthe .conf

use in .a sealed system in whichboth the air forV combustion and the exhaust from the heater canv be takenfrom or-to.remote points. Such a heater is illustrated inthe present assignees copendingf application of Theodore Yg Korsgrenv and Frank' A. Ryder, for Heating systems, illed May-.28,` 194:5,V Serial Number-596,130, now abandoned: t Yet another object vof the presentinvention is to provide anovel sealed gas heater havinga burner of the atmospheric or semi-secondary air type. i'

Another object. is to provide a novel floor furnace typeheater which can beinstalled without change'intheistructuralelements of a conven` tionally constructedhouse or other building. :Still another object. of the present 'invention ist@ provide: a. novel'heater ofthe 'above-'type' which can be manufactured at low cost and which will :give long', trouble-*freefand efiicientservice in'operation.

other objects and advantages win-become ajo:i parent from the followingdescription of aprei" ferred embodiment of my invention which is il-- lustrated in the accompanying drawings.'

Y.' In L the drawings, vinv which "similar characters of reference refer to similarwpartsthroughout the several-views:

Fig. 1 is a somewhat diagrammatic longitudinalr sectional view, takenon avertical plane"substan-` tially mediallythrough a heater embodying the -present invention; "f" Y' tal sectional view along the` Fig. 2 is a horizon line 2 2 of Fig. 1 lookingV upwardly as indicated by the'arrows; and' V' Fig. 3.is a -horizontal sectional view similar to Fig. 2 but taken 'rin 'the'direction' indicated Vby' the Varrowsalong the line 33=ofFi'g.-1.

--Inasmuch` as theY f present invention relates`v principally Vtothe nconstruction and operation fof:`

the. heating portion of a fiooriurnaee asV opposed' y upper end is secured,vas.by

troly systemhas not been'illustrated since itrnight tend to obscure the invention.

Referring -to Fig.. l ofthe drawingathe heater mechanism is enclosed withina vertically disposed. generally cylindrical casev I0,- the Alower end.A of.

which is Yclosed by. a bottomv iplate I2, while the spot welding or rivet- The ring .I4 is circular will lit into a circular ing, to a flangedring I4; and is of such a-size that it opening cut through theifloor of a building be-` tweenthe conventional jo'istfspacing so that no Vstructural members of the house .or other build-y ing need be cut in installing the heater. -Thus no special'box type reinforcingofthe floor structure is'necessary.- 1, '1 *wThe"spacewithinfthecasing I0 is divided into two compartments-by a; vertical partition` I6. As illustrated in Fig. 1, the space to the-.left of the partition 1 is indicated. by the numeral I8 and houses the'heat exchanger ande burner ,portionof the heater, aswell as'some control and regulatin'gequipment, .whilethe right hand space 20 en-y closes the blowers and other operating mechanism whichwill bedescribed presently. .Y y Air to be heated passes downwardly'from the room, through a vgrillr22 formedin the ring. |41

and located above the space 20 -and intothe inlet 24 of a-blower 26. Thebl'owerhas a Slrocco type wheel 28 Ywhichforc'es-theair into the usual typeV scroll case3|l from-:which itV passes throughwthe partitionl 6to a' plenumchamber 32'of the burner and heatv exchangerfmechanism indicated gen-' erally bythe numeral 34. As will be explained in greater detail presently, the air passes upwardlyf from Vthe plenum chamber 32. through the heat exchanger portion'f of 1 the heater andA into a plenum chamber Fromhere the` heated air passes loutwardly through a grill `38 located*` above the heat -ex changer and within-the ring I4'. VIf desired, the outlet grill 38.5 and the inlet grill '32 can be formed as a single casting'or' stamping'which rests'rin nested removable relation to the ring I4 as'shown;

The blower 26 is'fcomprised ofthe usual type scroll ca`se30 which 'houses a/Sirceo'rotor 28i mounted upon a shaft 40. ThisY shait extends Yvertically andis'journaled'at its upper end in a bearing l42mounted'in`the spider 44 attached to the fface off the-'scroll case 30.1 The "lower- 36 above the lheat exchanger.-

end of the shaft extends through a similar bearing 66 carried at the lower face of the scroll case 30. Beyond the bearing 4t the shaft 40 carries a second blower wheel 48 of the centrifugal type mounted to rotate within a second scroll case 501. The two scroll cases 30 and 50 are arranged back to back with the scroll case 5i) having an inlet opening at the lower face thereof connected to an elbow 52 which extends through the heater wall and there is connected by a pair of matched iianges 54 to a combustion air intake pipe 56.

In a position between the upperface ofthe scroll case 30 and the upper bearing 42, the shaft 40 is provided with a pulley 58 connected by a V belt A611| to a drive pulley 02 secured to the shaft of an electric motor 64, themotor being mounted upon the scroll case by a bracket 65. It is apparent, therefore, that whenever the motor 64 is energized, the shaft 40 will be rotated, thus driving the Sirocco-type wheel 28 which draws in Ventilating air through the grill 22, and centrifugal-type blower wheel 48 which draws in corn-V bustion air through the pipe 56. If desired, the scroll cases 30 and 50 can be formed as a single casting or fabricated .member as .shown in Fig.; 1J or if preferred, these two blowers can, of course, be separate.

The outlets ofboth scroll cases extend rthrough the partition I6 andthe combustion 'air scroll case 50 is connected through 'a kcombustion airv tting '6B having a Venturi throat .t8 to an elbow 10 equipped with a flange :12 .by which it is connected toa combustion air plenum chamber 14,'

the purpose of which will lbe. explained presently. The outlet of the ventilating'j'air-scroll case. 30 is connected to the ventilatingair `plenum chamber 32 previously'mentioned."

The burner and heat exchanger portion .of theV apparatus isrgenerallyzovalin vshape'and is vertically mounted by means of brackets 1S which are welded to the shell 18 of the-heat exchanger and bear against the -side wall and the partition I6.

As best seen in Figs. 2 and 3, the combustion chamber and a portion of the heat exchanger is formed of a single sheet 19 of stainless steel or other heat and corrosion resistant material which is first bent to deep furorm, with'the'upper straight portions of the U subsequently being bent outwardly and around Ygenerally. parallel to 'the more central `portion of the sheet until the endsV overlap in a position opposite the center ofthe sheet. At this point they are weldedtogether as at 80. The 1bentandwelded sheetV ,-'l9 iszene closed within Van oval chamber bounded at the,

outside by similar metalysheetsf82formed in two halves, thehalves beingV provided at Y-their edges the sheet 82 around thepopening, The exhaust.

fitting 88 extends through the side wall |0 .an:l is connected to a length of exhaust tubing 90 by means of matchedgilanges 82. 1

The heat exchanger .iust-describedprovides a` combustion space 94 which is generally oval in cross section. This ycombustion space is .bounded by the Vinner surface efY the lsheet 'I9 v and at its of Ythe case 05 i4 and the enclosing oval case made up of the sheets 82.

The passages 98 and the chamber 04 are closed at their ends by an upper header plate |00 and a similar lower header plate |02, both of which are flanged at their edges and welded to the sheets 'I9 and 82. These header plates are formed with U-shaped slots which permit Ventilating air to enter the U-shaped space |04 located between the outer surface of the inner portion of the sheet 19 and the inner surface of the cuter portion of this same sheet. l i e "The 'heatKA exchanger .just described is kept in alignmentby l"means oi" 'smallVr U-shaped sheet metal spacer elements |06 which extend longitudinally within the slot |04 and are welded to theinner portion of the sheet 'I9 while resting y! with their centers against the outer portions of this sheet. I

. Similarly, .longitudinally extending spacer elements |08 are welded to the outer surface of Y the ova'lisheets V8 2 and space the oval jacket 'I8 therefrom, this jacket 18 preferably being made in two halves which are welded together, as at H0.

At its lower end, the outer case Isis provided with .brackets ||2 arranged .in spaced relation around the periphery towhich a casing ||4 which forms the ventilating air plenum chamber 32 is connected by means of bolts :l i6.

The-combustion air plenum lchamber '14 is comprised of a compartively Adeep drawn oval cup I8 located within the Ventilating airplenum chamber-32 and welded to the .lower header .plate |02 which the-upper` surface thereof extending into a complementary shaped'iianged opening formed .in the header plata The lburner proper is comprised. of a tube |20 y somewhat longer than the combustion chamber outer end, that is, at thepoint where the sheet Y 19 is rolled over and bent backWa-rdly as at 95, the combustion 'space 04 is connected to two reversely extending passages 98 formed between the backwardly bent portionsjof the sheet 19 V94. It is positioned vertically within the combustion chamber and' extends through an opening |22vin the upper surface of 'the combustion air plenum chamber'` cup H8.Y At its vupper end the burner tubev |20is closed and may be secured .Ainplace .by welding to the upper header plate |00. It is also supported by means of a bracket |24fwhich secures the lower portionof the tube to the'side wall-,of the cup HI8: VVThe side of the tube |20 toward ftheexit end of the combustion chamberisgprovided .with-a jet strip |24 Awelded thereto lwhich has a plurality of jet openings |26 formed therethrough so that a gas and air mix-V ture under pressurerlnrthe tube 20 will issue through the iet `passages |26- and be directed toward the opposite end of the combustion chamber. A bell mouthV |28 is rformed' at `the lower end ofthe tubeV |20'and is-in alignmentwith an aspirating gasnozzle |30l which is connected by means of a supply pipe |32 to a gas regulator valve |34 of any suitable type. The one shown isillustrated land described in detail in the previously mentioned Ryder case and acts to proportion the rate ofV gas ilowin accordance with the pressure differential produced between the venturi`68 andra small scoop-like connection |36 located Somewhat downstream of thefmost constricted por-tionI of the venturi.

Asamay be seen in Fig.l 3, theopening- |22 inl chamber 94 to vcomplete the combustion of lthe gas and air mixture introduced through the tube |20,1the mixture being ignited by a spark plug |38 threaded throughA a bushing |40 ywelded to the header -v platev| adjacent` the vend of-the, jetV strip |24. Although not shown,.thisrntrltplug:v is connected to a usualtype ignition transformer. The heater above described operates in the following manner. When themotor y64 isener-xz gized; therebydrivingblower wheels 28;V and 4 8, Ventilating air is drawndownwardly through` the grill321andiblower30 and forcedffinto thevene tilatingf'air plenum chamber 32;, This air passes; upwardly through the longitudinally extending U-shaped slot |04 and through the oval spaCe provided between the Ventilating air case 18 and the outer combustion air sheet 82. The ventilating air, therefore, absorbs heat from theentire surface of sheet 19 as well as from the entire surface of the sheet 82, both of these sheets'being heated by the hot products of combustion which pass from the combustion chamber 82 to the exhaust 88. The hot Ventilating air passing from the heat exchanger at the top thereof flows into the plenum chamber 36 and thence through the grill 38 to the space to be heated. Meanwhile, air for combustion has been drawn in through the pipe 56, elbow 52 and blower 50 and has been forced therefrom through the elbow fitting '.to the combustion air plenum chamber 14. A portion of this air passes through the opening |22 -into the combustion space 94 where it surrounds the burner tube and jets |26. Anotherliportion of the combustion air is aspirated by gas under pressure flowing through the pipe |32 and from the aspirating nozzle into the bellv mouth opening |28. Although it forms no partv of the present invention, it will be appreciated` that the valve |34 supplies gas under pressure: to the aspirating nozzle |30 as soon as combustion air iiows through the venturi 79 in suilicientguantity. As is fully explained in the previously referred to Ryder application, the rate of gas fiowis regulated by the valve |34, so that as the combustion air rate increases the gas rate also increases. The rate of heat output, therefore, can be controlled by the electric power input to the motor ,84. Y The size of the bell mouth |28 and the aspirating effect of the nozzle |30 are so proportioned that the mixture of gas and air withir'ifjhe tube |20 is too rich to burn properly. Thelkgas, however, has been sufficiently diluted, so that as soon as it issues from the jets |26 and mixes ,with the additional portion of the combustion air-supplied through the opening |22 the mixture quickly reaches the proper ratio for eilicient combustion. As previously mentioned, the hot products of combustion pass from the combustion'ffchamber 94 into the two rearwardly extending passages 88 and to the exhaust connection which leads to the exhaust pipe 88. -j 'j Having described my invention, what I claim as new and useful and desire to secure. by Letters Patent of the United States is:

1. In a gas heating appliance, the c mbination comprising a fuel gas nozzle, means tofsupply gas under pressure to said nozzle, a combustion air aspirator associated with said nozzle so that flow of gas from said nozzle aspirates air',` to form a gas and air mixture, a longitudinallyv extending member of horseshoe-shaped cross section deiining a combustion chamber having a', generally elliptical cross sections, tubular gas burner contained longitudinally in said combustion chamber near the closed side Vof said horseshoe-shaped member and having a plurality of mixture outlet openings therein directed generally toward the open side of said horseshoe-shaped member, conburnerL-fineans 'forminga plenum-chamber en-' closing said aspirator,` means 'forming' a secondarylY 1 combustion airfioW- path" from saidf plenum 6 surew'hreby ar portion of 'saidv air under pressure in said plenum chamber flows directly to said combustion chamber while another portion of said air under pressure is aspirated by said aspirator before being delivered to said combustion chamber.

2. In a gas heating appliance of the type described, a longitudinally extending member of horseshoe-shaped cross section deiining a combustion chamber of elliptical cross section, a tubular gas burner having a plurality of mixture outlet openings therein directed generally toward the open side of said hors contained longitudinally in said combustion chamber near the closed side of said horseshoeshape sure for said burner and said combustion chamber, an exhaust connection for the last said means, an inlet connection for said sealed enclosure, a source of combustion air under pressure, means connecting said source to said inlet connection, and means for supplying a mixture of fuel gas and air under pressure to said burner whereby said mixture burns in an atmosphere maintained above the ambient `air pressure.

3. In a gas heating appliance, the combination comprising a fuel gas nozzle, means to supply gas under pressure to said nozzle, a combustion air aspirator associated with said nozzle so that flow of gas from said nozzle aspirates air to form a gas and air mixture, a longitudinally extending memberY of horseshoe-shaped cross section defining a combustion chamber having a generally elliptical cross sectiona tubular gas burner contained longitudinally in said combustion chamber near the closed side of said horseshoe-shaped member and having a plurality of mixture outlet openings therein directed generally toward the open -side of said horseshoe-shaped member, conduit means connecting said aspirator to said burner, means forming a plenum chamber enclosing said aspirator, means forming a secondary combustion air iiow path from said plenum chamber to said combustion chamber, means forming a heat exchanger connected to receive hot products of combustion from said combustion chamber, said heat exchanger having an exhaust connection, said heat exchanger forming means and said member deiining Ventilating air passages encompassing said combustion chamber, and blower means for delivering Vcombustion air to'said plenumy chamber under pressure whereby a portion of said air under pressure in said plenum chamber flows directly to said combustion chamber while another portion of said air under pressure is aspirated by said aspirator before being delivered to said combustion chamber.

4. In a gas heating appliance of the type described, a longitudinally extending member of horseshoe shaped cross-section defining a combustion chamber of elliptical cross-section, a

tubular gas burner having a plurality of mixture outlet openings therein directed generallyY toward the open side of said horseshoe shaped member contained longitudinally in said combustion chamber Yto Vsaid combustion chamber, means forming afiheat exchanger connected to receive hotproduc'ts of combustion from said combustion chamber, said' cheat;v exchanger having an exhaustif connection, andv blower means for delivering com:- bustion airV tosaid plenum chamber underpres"y eshoe shaped member4 d member, means forming a sealed enclo-r chamber near the closd sigdezxof'saiid hQrsgshQef- BfEEEREHGES! CHE!) Y Shaped memberm'ens forming' an fin-down@ Q15 vThe ifillowiiifzgf references are of; record in the sa'efl burner andjsaici combustion chamber; means n far admitting. c:0.11lleustiicm` air; tQ said elflflosureL me of this Patent' meansfor emitting pi-Qductsl of Qombustionvfrom, g;V UNL'IED SIAIEISh said enczlosure,means for promoting the flow of Number, Naime Date ail-inta sai-d enclosure and the products 0f com; 1392.15 McKee, f Y Dec. 27 1932-' bustion from said enclosure, and means for sup- IQQSM,A RassA An 2', 1935. plyi-ng a mixture of fuel gas and air 15o, said 250771424 Levey;f "7"`Apr- 1931; burner. 1Q 2,334,336 Honneuse sept. 18,1945:

THEODORE. Y. KoRsGREN. 

